The ammonia oxidation reaction has many important applications. One important application is in ammonia cracking systems where the combustion of ammonia is used to provide heat for the ammonia cracking reaction to generate hydrogen from ammonia, e.g. as shown in WO 2011/107279.
Another application with a much larger demand than the first one is for the removal of slip ammonia after ammonia assisted selective catalytic reduction (SCR) of automotive diesel engine exhaust. Diesel engine generates nitrogen oxides (NOx) which is seriously harmful for the human health and in order to follow the regulations, the exhaust of the diesel engines is treated for NOx removal. One of the widely used treatments is indeed SCR, where ammonia is added to the exhaust. In order to bring the NOx concentration level to the expected level, the ammonia added is typically more than what is required by the reaction. This results in ammonia slip that needs to be removed by combustion. A third important application is the removal of ammonia from biogas generation plant, which, if not removed, generates NOx after combustion.
For all these applications low temperature light off of ammonia oxidation is required. Currently the catalysts employed in these processes for ammonia oxidation are based on scarce and expensive metals, such as Pt and Pd, e.g. as described in U.S. Pat. No. 5,587,134 and U.S. Pat. No. 7,722,845.
Hence, an improved catalyst would be advantageous, and in particular a more efficient, having higher catalytic activity and/or less expensive catalyst would be advantageous.